The Use of EMTP® by an Utility

If you wish to contact the authors of the newsletter, please contact POWERSYS
The Use of EMTP® by an Utility
Powersys has discussed EMTP® with Mr. Poujade and Mr. Deneuville who are research engineers from the R&D department of EDF (Electricité De France). EDF is the first producer and supplier of Electricity in France.

The mission of the R&D department is to help the operators of all electricity production sites to buy, put under service, maintain and troubleshoot all the electrical machines (transformers, power generators and motors).

EMTP® usage:
• What is your use of EMTP®?
EDF has been amongst the first companies to use EMTP®. We use EMTP® to study transients in electrical network for various types of studies (fault and protections, microgrid, lightning, switching, ferroresonance, harmonics…) and all voltage levels.

• Has your use of the software evolved since then?
Yes. We are now using advanced features (mainly scripting and link with Matlab) much more often.

EMTP® and your work:
• How did your company benefit from using EMTP®?
EMTP® helps our company to solve a very large range of technical electrical issues. It is used for nuclear power plants as well as wind farms, but there are many other EMTP® applications in the company.

• Can you describe a specific project in which EMTP® had a key contribution on study time and accuracy of results?
One of the numerous applications of EMTP® is the simulation of lightning strike. For instance, it is currently used at EDF to predict the overvoltages which would propagate within the electrical network of some power plants. This calculation is used to avoid the installation of potentially useless surge arresters and to make sure that the lightning overvoltages will not damage apparatuses. It requires precise high frequency models of overhead lines, cables, transformers, generators and motors. As EMTP® offers a large range of components and features, it is easy to incorporate models that have been developed by our manufacturers. This helps us to avoid modeling the complete electrical network: this is a significant gain in time but also in accuracy because the key components are modelled by their designers.

• Is there anything that EMTP® allows you to do that you could not do before?
Yes, the ability to "see" and better understand phenomena in electrical networks. For example, we can see how a motor behaves when faced with a short circuit and we can also determine in which configurations the conventional calculation methods for short circuit currents can be improved.